Answers are grounded in this paper and cite their sources.
Cu(SbF6)2-AdamBox and copper(II) bis-(5-tert-butylsalicylaldehydate) catalyze the Michael addition in neutral media. Mechanistic studies, based on UV-vis, IR, and electrospray ionization mass spectrometry (ESI-MS), suggest that copper enolates of the beta-dicarbonyl formed in situ are the active nucleophilic species.
No takes yet. Share an insight, caveat, or question.
Comelles et al. (2004) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: